Wrench.



L w. HAMLETT.

WRENCH.v APPLICATION FILED DEC. 7. I915.

Patented; Feb; 20,1917.

JAMES W. HAMLETT, OF PORT LAVAGA, TEXA$.

WRENCH.

This invention contemplates an improved wrench and has as its primary object to provide a device of this character wherein the wrench may be easily and quickly ad-,

justegl The invention has as a further object to provide a wrench wherein, when adjusted, the coacting elements of-the wrench will be securely held in fixed position and wherein strain upon the movable jaw of the wrench tending to shift it away from the fixed jaw, will tend to urge the locking pawl of the movable jaw into more secure engagement with the shank of the wrench for holding the movable jaw fixed.

The invention has as a further object to provide a wrench wherein the locking pawl may be released by simply pressing downwardly upon a releasing button or lever therefor so that the wrench maybe easily manipulatedby one hand of the operator.

And a still further object of the invention is to so mount the releasing button of the lever-for the locking pawl of the wrench that objects cannot easily strike the said lever, in the manipulation of the wrench, to accidentally release the said pawl.

Other and incidental objects will appear as thedescription proceeds and in the drawings whereinI have illustrated the preferred embodiment of the invention and wherein similar reference characters designate corresponding parts throughout the several Views,

Figure 1 is a side elevation of my improved wrench,

Fig. 2 is a similar view showing the movable jaw of' the wrench in section and particularly illustrating the mounting of the locking pawl of the said jaw and the releasing button or lever for the pawl,

Fig. 3 is a detail perspective view showing the locking pawl'detached, and

Fig. 4 is a fragmentary view illustrating a slightly modified construction of releasing button for the pawl.

In carrying out my invention. the wrench is provided with a straight shank 10 formed Specification of Letters Patent.

Patented Feb. 2o, 1917.

Application filed December 7, 1915. Serial No. 65,534.

upon its inner edge with a rack or series of teeth 11 and having a fixed jaw 12 arranged atone end thereof. The jaw 12 is preferably integral with the shank 10 and is extended'at one end to provide a hammer face '13.

Slidable longitudinally of the shank 10 is a movable jaw lladapted to coact with the fixed jaw 12 and provided with an internal recess 15. Entering through the forward edge of the jaw and 'comnmnicating with the recess 15. is an opening 16. At the inner end of the recess. the bod of the jaw is cut awav to provide a concave seat 17 at the junctidn of the side and inner end walls of the said recess.

Pivotally'mounted \vit'h'n the recess 15, is a locking pawl 18. the head of which is provided at one end witlra' .reduced bearing portion 19 having a convex outer face and at its other end withteeth 90. Extended laterally froni the head of the pawl is a reduced shank 21 in which is formed a slightly elongated opening 2-2. The reduced portion 19 of the head of-the pawl is provided with a suitable opening23-through which isfreely fitted a pivot pin g1 of .-less diameter than the said opening and conpeeting tine pawl with the jaw. with the teeth 20 of the head thereof adapted to engage the teeth 11 of the rack and with the convex face of the reduced portion 19 of the head of the pawl confronting the concave seat 17 of the. movable jaw. The shank '21 of the pawl is arranged to extend longitudinally within the recess 15 toward the opening 16 and is engaged by a guide pin 25 seated at one end in the forward end wall of the movable jaw and projecting into the recess with its opposite end extending freely through the opening 22 in the shank 21 ofthe pawl. Interposed between the forward edge wall of the said aw and the free extremity of the shank is a helical spring 26 which surrounds the guide pin 25 and is normally adapted to urge the pawl to engage the rack 11.

Pivotally mounted'in the opening 16 of the jaw 14 is a releasing button or lever 26 for the pawl. This lever is preferably provided with a knurled head 27 so that it may be easily. operated and the shank of the said lever is longitudinally curved to extend within the recess 15 toward the pawl 18 and engage beneath the free extremity of the The pawl-is thus mounted to lift the free extremity of the shank 21 against thetension of the spring 26 so that the pawl. will rock upon its pivot to move the t eth thereof out of; engagement with the teeth 11 of the rack. The movable aw may then be adjusted away from the fixed jaw and it will be noted that this operation may be easily accomplished without the use of both hands of the operator. Thus, the wrench may be easily and quickly manipulated. Upon the release of the lever 26. the spring will'again urge the pawl to engage the shank 10 to hold the movable jaw fixed.

The purpose in freely mounting the pawl 18 upon its pivot pin '24 will now become apparent. It will be seen that when the pawl is in engagement with the shankf'lO,

the head of the pawl will occupy a position oblique to the longitudinal axis of the shank with the major length of the head disposed below the plane of the said pivot'pin. Consequently. when stress is exerted upon the movable jaw tending to shift the said jaw downwardly upon the shank away from the fixed jaw, the head of the pawl will act as a cam between the movable jaw and the shank and will bind between the shank and the seat 17 with the convex face of the reduced portion 19 of the head of the pawl engaging within the said seat. It will therefore be clear that the greater the downward stress upon the movable jaw, the more securely will the pawl be moved to bind between the shank and the movable jawto lock the said jaw in fixed position upon the shank; In this connection, it will be observed that the seat 17 is formed in a solid portion of. the body of thewrench' so that the cam action of the pawl will be exerted against the thickened portion of the wrench body and the said seat will therefore pr vide a rigid abutment for the pawl.

It will now be observedthat the head 27 of the lever 26 is received withina suitable notch 29 formed in the outer lower corner of the movable jaw and'the forward edge of the said jaw is provided with a thickened portion or shoulder. 30 adjacent the said notch, the shoulder projecting laterally and outwardly from the plane of the head 27 of the lever. The head of the lever is thus shank 10.

"mounted entirely within the lines of; the

this modification, the operating lever includes a headed button designated 32 and a rock arm pivotally suppo'rtcd within the recess 15 of the movable aw by a pin 2H.

The button 32 is provided with a shank which extemls within the said recess and is pivotally COIIIIGCtQfltO one end of thc said rock arm while the opposite end of the rock arm is engaged beneath the free end of the shank 21 of the pawl 18. By depressing the button 32, the rock a rni Will be moved to lift the pawl out of engagement with the Since the construction of this modified form otherwise in accordance with the preferred construction of the inventioin a. further description thereof is obviously unnecessary.

Having thus described my invention. what I claim and desire to secure by Letters Patent is:

1. A wrench including a shank provided with a fixed jaw. a movable jaw adjustable upon the shank to coact withthe fixed jaw. the movable jaw being formed with a concave seat. and a pawl loosely pivoted to the movable aw and provided with a head hav ing a convex portion confronting said scat. the head of the pawl being movable to engage the shank in a plane upon one side of said pivot whereby pressure upon the movable jaw tending to urge it away from the fixed jaw will act to rock the pawl upon its pivot to a position with the pawl wedged between the shank and the movable jaw with the head of the pawl engaging the shank and with the convex portion thereof abutting said seat.

2. A wrench including a shank having a fixed jaw, a movable jaw adjustable upon the shank. and a pawl having a head loosely pivoted to the movable jaw and movable to JAMES \V. HAMLETT. [n s] 

